摘要 |
electrical engineering, namely method and apparatus for generating outlet characteristics of power source for electric arc welding, manufacture of welded constructions in different branches of machine engineering. SUBSTANCE: method comprises steps of forming outlet voltage of power source by summing vectors of two voltages whose modules, phase angle between them and summed voltage are functions of welding electric current. Apparatus includes transformers with common secondary winding; primary windings are connected with different phases of three-phase circuit, one winding is connected by its beginning terminal and other winding - by its ending terminal with two phases. Other terminals of said windings are together connected with one terminal of controlled phase-shifting unit whose second terminal is connected with third phase of supply mains. Invention allows to change profile of Volt-Ampere characteristics of power source and to use transformers of any type. EFFECT: less power of control devices for reducing voltage of power source from idle period value until necessary operational value. 2 cl, 6 dwg
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